Two direction shock absorbing troughing idler assembly



April 19, 1966 R. F. LO PRESTI TWO DIRECTION SHOCK ABSORBING TROUGHING IDLER ASSEMBLY s Sheets-Sheet 1 Filed March 5, 1962 INVENTOR. 0 [/0 /E/Z,

April 19, 1966 R. F. LO PRESTI TWO DIRECTION SHOCK ABSORBING TROUGHING IDLER ASSEMBLY Filed March 5, 1962 3 Sheets-Sheet 2 mf AW/w April 19, 1966 R. F. LO PRESTI TWO DIRECTION SHOCK ABSORBING TROUGHING IDLER ASSEMBLY Filed March 5 1962 3 Sheets-Sheet 5 United States Patent 3,246,736 TWG DEREiTTH'PiN SHGQK ABSQRETNG TRQUGHHNG KDLER ASSEMBLY Roy F. lilo Presti, (Ihicago, IlL, assignor to Goodman Manufacturing Company, Chicago, EL, a corporation of iliinois Fitted Mar. 5, 1962, Ser. No. 179,278 6 Claims. (Cl. 198--2tl2) This application is a continuation-in-part of my copending application Serial No. 322, filed January 4, 1960, now abandoned.

This invention relates generally to flexible belt conveyors, and specifically to a quickly and easily positionable belt training troughing idler assembly for use in such conveyors.

Rope sideframe conveyors of the type illustrated in the Craggs et a1. Patent No. 2,773,257 have come into increasingly widespread use in recent years due to their many inherent desirable features. Among these are low cost, large carrying capacity, ease of installation and maintenance, and easy adaptability to any conveyor environment.

These conveyors generally comprise a pair of flexible sideframes, such as wire ropes, which are trained along a conveying course such as a mine drift or the like. The ropes are supported at spaced intervals in generally parallel relationship by suitable supporting structure such as ground support stands or overhead hanger assemblies. In the Craggs et a1. patent, the supporting structure takes the form of a plurality of support stands, each having a seat at its top which receives the rope sideframes.

A plurality of troughing idler assemblies are suspended from the ropes at spaced locations. These idler assemblies include a plurality of generally axially aligned rollers which form a continuous bed for the conveying reach of a flexible conveyor belt. The return reach of the belt is usually supported directly beneath the conveying reach by a plurality of return roller assemblies. The return roller assemblies may be suspended from the ropes or other suitable structure.

A great many troughing idler assemblies have been developed to meet specific needs in specific industries. Many have overlapping features but for purposes of discussion they may conveniently be classified as flexible, semi-cradled or cradled idler assemblies.

A fully flexible idler assembly is illustrated in the Craggs et a1. patent. It consists of a plurality of rollers connected at their abutting ends for fiexure With respect to one another in a vertical plane. The outer ends of the flanking rollers are then connected directly to the rope sideframes. This type of structure is of optimum simplicity and has a high carrying capacity. The tension path from the center roller to the ropes passes through the wing rollers.

A semi-cradled idler assembly is illustrated in application Serial No. 704,483, filed December 23, 1957, now abandoned, and asigned to the assignee of this application. The rollers are generally free to flex vertically with respect to one another, and usually horizontally also, but the assembly is connected to the rope sideframes through a frame which supports the wing rollers. in effect, the tension path from the center roller to the rope sideframes bypasses the wing rollers.

A good example of the cradled idler asembly is illustrated in the McCallum Patent No. 2,851,151. The rollers in this construction are carried in a frame structure which in turn is connected directly to the rope sideframes. The frame structure may include members spanning all or a portion of the conveyor and may be rigid,

as in the McCallum patent, or semi-rigid.

In any conveyor system utilizing troughing idler assemblies, including the rope sideframe conveyors above described, the problem of maintaining the belt centered or trained as it passes over the idler assemblies is encountered to some degree. Detraining of the belt has serious effects. If there are objects in line with the edge of the outermost rollers, the belt may detrain so far as to strike them and fray along its edges. As soon as the belt begins to detrain, the optimum troughing contour is lost and accordingly the carrying capacity of the conveyor is substantially reduced. In addition, a detrained belt sets up stresses and strains in the conveyor which requires additional power to maintain operation and may hasten fatigue failure.

The theory behind the detraining of belts in conveyors is fairly well known. In essence, it is pretty well established that the friction between the belt and roller exerts a training etfect or force on the belt as it passes over the roller. Experiments have shown that this training effect is exerted by the roller on the belt in a direction substantially perpendicular to the longitudinal axis of the roller. When the direction of a moving belt is substantially perpendicular to the longitudinal axis of the roller therefor, the belt will remain centered, or will run true, over the roller. Should the roller be so oriented that one end is located rearwardly of the other end, detraining will usually occur.

Various remedies for overcoming belt detraining characteristics have been proposed. One well-known expedient is to cant the outer or wing rollers in a multiple roller troughing idler assembly in the direction of belt travel. In general, however, these attempts at training the Wing rollers have been only partially successful, because it is usually only possible to train the belt in one direction. In other Words, although it is rather easy to build unidirectional belt training characteristics into a conveyor system, it is quite another thing to provide two directional belt training structures.

Accordingly, a primary object of this invention is to provide a two directional belt training troughing idler assembly for use in flexible belt conveyors.

Another object is to provide a flexible belt conveyor belt training troughing idler assembly which can be quickly and easily reset to a reverse training position upon reversal of the direction of belt travel.

Another object is to provide a two directional belt training troughing idler assembly in which the tension path from the center or intermediate rollers to the troughing idler assembly supporting structure is offset rearwardly from the longitudinal axes of the wing rollers so that the inward pull on the supporting structure keeps the assembly in place once it is properly positioned.

Yet another object is to provide a two directional belt training troughing idler assembly in which the means for connecting the troughing idler assembly to the conveyor supporting structure and the wing roller training means are combined into a unitary structure.

Yet another object is to provide a belt training troughing idler assembly of simple construction and containing a minimum of parts.

A further object is to provide a belt training troughing idler assembly in which the greater the load and/or the higher the tension in the wire rope sideframes, the more firmly the wing rollers are maintained in a belt training position.

Yet another object is to provide an extremely simple yet rugged multiposition belt training troughing idler assembly having great shock-absorbing ability which thereby enables impact loads to be received without danger to either the roller assembly or the belt training structure.

Other objects and advantages of the invention will become apparent upon reading the following description of the invention.

The invention is illustrated more or less diagrammatically in the accompanying drawings, wherein:

FIGURE 1 is a top plan view with parts omitted and parts in broken lines of a belt training troughing idler assembly embodying the novel features of the present invention;

FIGURE 2 is a plan view to an enlarged scale of a portion of the two directional belt training troughing idler assembly of FIGURE 1 with parts broken away for purposes of clarity;

FIGURE 3 is a view taken substantially along the line 33 of FIGURE 2;

FIGURE 4 is an elevational view, partly in section, showing another embodiment of the present invention;

FIGURE 5 is a top plan view of FIGURE 4;

FIGURE 6 is a partial sectional view to an enlarged scale of a portion of the embodiment illustrated in FI URES 4 and 5; and

FIGURE 7 is a view taken substantially along the line 77 of FIGURE 6.

Like reference numerals will be used to refer to like parts throughout the following description of the drawings.

In FIGURE 1, a troughing idler assembly for use in a flexible belt conveyor of the type illustrated in the Craggs et al. Patent No. 2,773,257 is indicated generally at 10. The troughing idler assembly includes a troughing roller assembly indicated generally at 11 composed of a center or intermediate roller 12 flanked by a pair of end or wing rollers 13 and 14. Although only one intermediate and two flanking rollers have been shown, it will be understood that any combination of a greater number of rollers than that illustrated may be employed without departing from the scope of the invention, and

the simplified three roller assembly is illustrated for convenience of description only.

Each roller consists essentially of a shell which rotates about a dead shaft. Referring to center roller 12 for example, the shell is indicated at 15 and the shaft at 16. Any suitable bearing means may be interposed between the shaft and shell to provide a low coefficient of friction therebetween. The ends of shaft 16 are connected by pivot pins 17 and 18 to the inner ends of universal joint members 19 and 20. The outer ends of the joint members are connected as by pivot pins 21 and 22 to the dead shafts 23 and 24 of wing rollers 13 and 14, respectively. Although in this instance universal joint members comprising, in effect, two pairs of cars disposed perpendicularly to one another have been illustrated, it will be understood that any suitable structure may be utilized, so long as provision is made for swinging of the wing rollers in a generally horizontal plane through at least a limited arcuate path about their points of connection to the center roller. In this instance, it will also be noted that the universal joint members enable the wing rollers and center rollers to flex in a generally vertical plane with respect to one another so that the outer ends of the wing rollers may move towards and away from one another under load conditions.

The outer ends of wing roller shafts 23 and 24 are secured to a pair of sliding bracket assemblies indicated generally at 30 and 31. In this instance, the bracket assemblies include a tension distributing assembly comprising tubular sleeve members 32, 33 welded to generally U-shaped plate members 34, 35. The outer ends of the wing roller shafts 23, 24 are rigidly, non-rotatably received in the tubular sleeve members 32, 33 and secured by any suitable connecting means such as rivets 36, 37.

As best illustrated in FIGURES 2 and 3, each of the U-shaped plate members 34, 35 includes a pair of legs, one overlying the other. The forward and rearward extremities of the legs are offset a considerable distance on either side of the projection A of the wing roller axis. A pair of tension transmitting members, which in this instance are illustrated as generally vertically axised pins 38, 39, and 4-0, 41 pass through aligned apertures in the upper and lower legs 42, 43 of the plate members. The pins or bolts are so positioned that a space 45 extending the length of the bracket member is formed between the pins, the upper and lower walls 42, 43, and the inner wall 44 of the bracket member.

The bracket assemblies 30, 31 slide along races 50, 51 which in turn are welded or otherwise suitably secured to means for connecting the troughing idler assembly to the rope sidefranies 52, 53, such as rope clamps 54, 55. Since the particular means by which the troughing idler assembly is connected to the rope sideframes does not form an essential part of the invention, it should be understood that the showing is exemplary only, and will not be described further in detail. It should also be understood that since the roller assembly 11 is secured to the rope clamps 54, 55 through the bracket assemblies 30, 31, including the races 50, 51, the bracket assemblies are in effect part of the connecting means.

The races 50, 51 in this instance are formed from solid rods whose working faces 56, 57 are outwardly convex. The working faces terminate in bight portions 58, 59 which in turn are connected by short legs 60, 61 to the rope clamps. As can be most easily seen in FIGURE 2, the rod races are crowned as at 62, and the length of the race on either side of the crown is at least equal to,- or, as shown in this instance, slightly longer than, the distance between the sliding pins 33, 39.

The conveying reach 70 of a flexible conveyor belt is illustrated in solid in FIGURE 3, and is broken lines in FIGURE 1. The direction of belt travel is indicated at 71 in FIGURE 1.

A somewhat simpler, yet extremely rugged embodiment is illustrated in FIGURES 4 through 7. In this embodiment the rollers 12, 13 and 14 are universally connected by universal joint members 19 and 20 as before. In this instance, however, the outer end of wing roller shaft 23 is connected by pin 36 to a collar member 75 which in turn is welded or otherwise rigidly secured to an outwardly extending plate 76. An elongated slot 77 is formed in the plate 76 at a location spaced substantially directly transversely outwardly from the outer end of collar member 75. A plurality of overlapping recesses or depressions 78, 79, 80, are formed in the outside edge of slot '77. Plate 76 terminates at its outer end in a downwardly extending flange or handle member 81.

A conventional rope clamp assembly is indicated gem erally at 82. An L-shaped channel member 83 is welded to the top and inner side of the rope clamp 82 in such a position that the top surface of the upper flange is substantially parallel to the undersurface of plate 76.

A tension-transmitting member, in this instance a pin 84, is welded to the inside surface of flange 83, as best shown in FIGURE 6. The shank extends upwardly above the upper surface of flange 83 a distance substantially equal to but no less than the thickness of plate 76. Any convenient means may be utilized for securing head 86 to shank 85, all of said means being considered within the skill of the art. It will be noted that in this instance the diameter of the pin shank 85 substantially conforms to the contour of each of recesses 78, 79 and 80, but this is not essential. A shank having a diameter larger or, more preferably, smaller than the diameter of the recesses or grooves may also be employed. It will also be noted that the grooves are relatively shallow and do not extend to even the halfway point around the circumference of the pin shank.

In FIGURE 5 the direction of movement of the belt is indicated by arrow 88. The direction of the belt training force exerted by the roller on the belt is indicated by arrows 89, 30, as will appear more fully hereinafter.

A Throughout the description of the invention. the terms inwardly and outwardly are based on directions looking toward and away, respectively, from the center or longitudinal axis of the conveyor. Thus, the right end of left wing roller shaft 23 is the inner end, whereas the left end of the right wing roller shaft 24 is the inner end. Likewise, the terms forwardly and rearwardly are based on the direction of belt travel 71 or 88, with the former term indicating a direction looking in the direction of belt travel, and the latter term referring to the opposite direction.

The use and operation of the invention is as follows:

This invention provides means for canting the wing rollers of a troughing idler assembly in the direction of belt travel, no matter in which direction the belt is moving. In FIGURE 1, for example, the conveying reach 70 is indicated in broken lines as moving in direction 71. In the position thereshown, load on the belt is transferred from the center roller and through the universal joint members 17, 18, the wing rollers 13 and 14, and the bracket assemblies to the rope sideframes 52, 53 which form the supporting structure of a rope sideframe conveyor of the type illustrated in the Craggs et al. patent.

The actual load transmission path or, for convenience, the tension path, does not extend to the rope sidefra-mes along the line A which is the projection of the longitudinal axes of the wing rollers. Since the tension path will tend to seek the shortest distance from rope sideframe to rope sideframe, load on the troughing idler assembly will be transmited from the wing roller shafts Z3, 24 to the tension distributing sliding bracket assemblies 30, 31, through the tension transmitting members or pins 39, 41, and then through the race members 50, 51 and rope clamps 54, 55 to the rope sideframes. The line B denotes the effective tension transmission path. As a result, once the tension distributing bracket assemblies 39, 31 are set in the position of FIGURE 1, they will stay put until re-orienfed into the opposite training direction, as illustrated by the phantom line of FIG- URE 2. Since the coefficient of friction between the sliding bolts 38-41 and the rod races 56, 57 is relatively low, the bracket assemblies 30 and 3 1 may be flipped easily to the opposite position.

It will be understood that although the race members 50, 51 have been illustrated with a substantial crown, this is not essential. The crown may be flattened out, for example, in which event a minor portion of the load will be transmitted partially through upper bolts 38, 40, along the effective tension path C. Preferably the pins are made for relatively heavy rod stock. However, by flattening out the crown of the rod races 50, 51, it is possible to use somewhat lighter bolts.

It will also be understood that although rod race members 50, 51 have been illustrated, the inventive concept is somewhat broader than this particular showing. For example, it is entirely within the scope of the invention to secure transversely inwardly extending apertured ears to rope clamps 54, 55 in place of the rod race members 50, 51 and insert appropriate pressure transmitting members, such as the bolts 3841, in the apertures. For ease of manipulation, however, it is highly desirable to utilize a sliding connection.

In the embodiment of FIGURES 4 through 7, the wing rollers 13 and 14 may be quickly moved to a new training position by pulling outwardly on handle 81 until the shank 85 of the pin 84 clears the recess in which it is located. The pin is moved forwardly or rearwardly as desired and then pressure on the handle released to let the plate drop into the selected recess. In FIGURE 5, for example, the plate 76 has been moved downstream and anchor pin 84 located in the furthermost upstream recess, recess '78. Because of the substanially rigid connection of wing roller shaft 23 to plate 76, the net effect will be to cant the outer ends of each of wing rollers 6 13 and 14 downstream with respect to the position of center roller 12. The net effect will be to exert training forces 89, 90 which are directed inwardly in a downstream direction upon belt 70.

Referring again to FIGURE 5, it will be noted that the angle formed between reference lines 91 and 92 represents an offset training angle. This angle may be on the order of two degrees, which experience has shown is quite sufficient to exert a definite retraining effect on a belt passing thereover. Base line '92 represents the theoretical line of force transmission from the center roller 12 to sideframe 52 but because of the offsetting of plate 76 with respect to anchor pin 84, line 91 represents the actual line of force transmission.

The embodiment illustrated in FIGURE 4 through 7 has an extremely high degree of built-in yieldability. If, for example, a shock load, such as a heavy rock, strikes one of the Wing rollers, the universal joints 19 and 20 will flex in the required direction or directions and the shock load will then be transmitted outwardly toward the ropes through the wing rollers. The transfer of the tension from plate 76 to anchor pin 84 will merely cause a rocking or pivotal movement of the plate and pin with respect to one another. Thus, the wear and tear formerly experienced in some idler assemblies on the individual ears comprising universal joints is completely avoided since the assembly gives under a shock load, and then returns to normal position after the shock load passes.

It should also be noted that in both the embodiments of FIGURES 1, 2 and 3, and 4 through 7, it is not absolutely essential that a universal joint be utilized. It is preferred, however, to use such a joint for shock transmission purposes and accordingly such joints have been illustrated in each embodiment. It should be clearly understood, however, that the basic concepts of the invention are applicable to nearly any multiroller assembly whether connected by universal joints or not.

One advantage of the flange member 83 and substantial overlap between head 86 and the plate 76 is the fact that high bearing pressures are distributed over a greater receiving surface. Thus, when the conveyor is loaded, and even when it is merely subjected to the transverse pull of the ropes, the points of contact between the flange and underside of the plate will be in the area indicated at 93. An area of contact between the head and plate will also occur in the area indicated at 94. A substantial overlap of mating areas reduces the bearing pressure on any given point.

It will thus be seen that in this embodiment particularly increased load and/or the tension in the ropes merely causes the plate '76 to seat more firmly against anchor pin 85 because of the relative location of the parts illustrated best in FIGURE 6.

Likewise, although the pressure distributing members 30, 31 are, broadly considered, part of the means for connecting the troughing roller assembly to the rope sidefrarnes, it is not essential that the connecting means include these elements. It would be just as feasible, for example, especially in semicradled and cradled constructions, to form the wing roller canting assembly separately from the means for connecting the balance of the troughing idler assembly to the rope sideframes.

Although a preferred embodiment of the invention has been illustrated and described, the showing is intended to be exemplary only, and not definitive. Accordingly, the scope of the invention should be limited only by the scope of the following appended claims.

I claim:

1. A belt training idler assembly, said idler assembly including, in combination,

a roller assembly including a plurality of individual rollers, and

means for connecting the roller assembly to the conveyor sideframes, said connecting means including, for each end of the roller assembly,

a pair of tension transmitting members, one of said members being attached to an associated sideframe, and having a generally centrally disposed load transferring portion, the other of said members being fixedly secured to the outermost roller and having a plurality of connecting portions at least one of which is laterally offset from the axis of the outermost roller, said laterally offset connecting portion of said other member being pivotably engageable with the generally centrally disposed load transferring portion of said one member so that said other member, and thereby its associated roller may move in a direction to cant the roller into a belt training position. 2. The belt training troughing idler assembly of claim 1 further characterized in that the individual rollers in the roller assembly are universally connected one to the other whereby each roller in the roller assembly, including the outermost rollers, gives in response to impact loads.

3. The belt training troughing idler assembly of claim 1 further characterized, firstly, in that the tension transmitting member connected to the roller is a substantially rigid plate extending generally outwardly from each outermost roller, said plate having an elongated slot, said slot having a plurality of overlapping recesses in its outside edge, and secondly, in that the tension transmitting member which is attached to the sideframe is a pin extending generally upwardly from a rope clamp assembly. 4. The belt training troughing idler assembly of claim 3 further including restraining means which prevent complete separation of the two tension transmitting members when in and out of seating engagement with one another while enabling relative pivotal and longitudinal movement with respect to one another.

5. The belt training troughing idler assembly of claim 1 further characterized,

firstly in that the tension transmitting member connected to the sideframe includes a slideway, said slideway being generally convex in a direction looking inwardly toward the center of the conveyor, and, secondly, in that the tension transmitting member carried by the associated outermost roller includes slide means which are slidable along the slideway to a position on one side of the crown in the slideway in which the roller is oriented in a training position.

6. A two directional belt training troughing idler assembly for use in a rope sideframe belt conveyor, said troughing idler assembly including, in combination, a roller assembly comprising a center roller flanked by a pair of wing rollers, the wing rollers being pivotally connected to the center roller for limited arcuate movement in a plane generally parallel to the conveyor belt moving over the troughing idler assembly, means for connecting the roller assembly to the rope sideframes of the conveyor, and means for maintaining the wing rollers canted in the direction of belt travel to thereby exert a training etfect on a belt moving thereover, said last named means including a sliding bracket member rigidly connected to the outer ends of the wing roller shafts, said sliding bracket member including two generally vertically axised pins, one pin being located on each side of the projection of the longitudinal axis of the wing roller, said sliding bracket member having an opening therein between the pins and the end of the roller shaft, and a rod race in sliding engagement with the vertically axised pins and connected to an associated rope sideframe, said rod race being convex in a direction generally outwardly from the center of the conveyor, the portion of the race lying on either side of the crown having a length at least equal to the distance between the vertically axised pins carried by the sliding bracket member to thereby enable both pins in the sliding bracket to be positioned completely on one side or the other of the rod race crown depending on the direction of belt travel so that the wing roller may be canted in a training direction with respect to the center roller.

References Cited by the Examiner UNITED STATES PATENTS 6/1959 Ogden 198202 5/1964 Kidd 198-192 

1. A BELT TRAINING IDLER ASSEMBLY, SAID IDLER ASSEMBLY INCLUDING, IN COMBINATION, A ROLLER ASSEMBLY INCLUDING A PLURALITY OF INDIVIDUAL ROLLERS, AND MEANS FOR CONNECTING THE ROLLER ASSEMBLY TO THE CONVEYOR SIDEFRAMES, SAID CONNECTING MEANS INCLUDING, FOR EACH END OF THE ROLLER ASSEMBLY, A PAIR OF TENSION TRANSMITTING MEMBERS, ONE OF SAID MEMBERS BEING ATTACHED TO AN ASSOCIATED SIDEFRAME, AND HAVING A GENERALLY CENTRALLY DISPOSED LOAD TRANSFERRING PORTION, THE OTHER OF SAID MEMBERS BEING FIXEDLY SECURED TO THE OUTERMOST ROLLER AND HAVING A PLURALITY OF CONNECTING PORTIONS AT LEAST ONE OF WHICH IS LATERALLY OFFSET FROM THE AXIS OF THE OUTERMOST ROLLER, SAID LATERALLY OFFSET CONNECTING PORTION OF SAID OTHER MEMBER BEING PIVOTABLY ENGAGEABLE WITH THE GENERALLY CENTRALLY DISPOSED LOAD TRANSFERRING PORTION OF SAID ONE MEMBER SO THAT SAID OTHER MEMBER, AND THEREBY ITS ASSOCIATED ROLLER MAY MOVE IN A DIRECTION TO CANT THE ROLLER INTO A BELT TRAINING POSITION. 